RESOLVED

The Power Resistor marked 10watt 1K5J gets very hot at ALL times (even when the power supply is sitting idle doing nothing)

So hot in fact that the cooling fan cycles on and off a lot to remove the heat.

I am wondering if I could resolve this by adding another Parallel 10W 1K5J resistor to the existing one? (Or if there is a better solution)
(I could not find a through hole, radial, wirewound resistor like this of greater than 10Watts)

 

The Power Resistor marked 10watt 1K5J gets very hot at ALL times

How hot is very hot? Is the derated dissipation specification being approached or exceeded?

I am wondering if I could resolve this by adding another Parallel 10W 1K5J resistor to the existing one?

You'd need to replace the existing resistor and use 2 3K resistors in its place. I don't know what that would buy you because the same power will be dissipated.

 

How hot is very hot? Is the derated dissipation specification being approached or exceeded?
You'd need to replace the existing resistor and use 2 3K resistors in its place. I don't know what that would buy you because the same power will be dissipated.

thanks Dennis.
I agree, the same power would be dissipated.
But unless I'm mistaken (possible) a larger watt resistor would dissipate the same energy and create less heat?

Of course, two - 3K resistors, since the current flowing through each would be cut in half.
Wouldn't that be the reason they would not run as hot even though dissipating the same energy?

That said, there doesn't seem to be room for two resistors, which is why I thought of just one, with a higher wattage rating.
Would that still get just as hot?

 

I found the answer in a previous thread......

https://forum.allaboutcircuits.com/threads/cooling-resistors-how-to.148870/

Thanks

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